1. Field of the Invention:
This invention relates to an antitumor formulation, and more specifically to an antitumor formulation containing an .alpha.,.alpha.-trehalose-6,6'-dicarboxylate and a lipopolysaccharide.
2. Description of the Prior Art:
A variety of antitumor formulations have been developed to date. As one of such antitumor formulations, an antitumor formulation containing, in combination, a natural cord factor and a lipopolysaccharide either as is or in a form attenuated its toxicity by a treatment with an alkali (may hereinafter be abbreviated as "LPS") has been known (U.S. Pat. No. 4,454,119).
Since a natural cord factor can be obtained from BCG cells or the like through cumbersome treatments or processing, it has been accompanied by such drawbacks that its yield is low and its production cost is thus high and it is by itself a mixture of many analogues and it cannot hence be obtained with certain constant quality.